Note: Descriptions are shown in the official language in which they were submitted.
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SACRIFICIAL ANODE SYSTEM
FIELD OF THE INVENTION
The present invention generally relates to sacrificial anode. More
particularly, it
relates to a sacrificial anode systern to be used in combination with grooved
pipes
and a method for maintaining a surface pipe system provided with a sacrificial
anode
system.
BACKGROUND OF THE INVENTION
it is known that corrosion imposes havoc on the grooved pipe industry. Grooved
pipe
technology is a method by which pipes and associated components are joined
together through a clamp or a coupling. In such configurations, the ends of
the pipes
to be joined and associated components have grooved interfaces that allow the
clamp or coupling to hold adjacent components together. The clamp or coupling
is
also provided with a rubber gasket or seal in order to seal the joint between
the
pipes.
Grooved pipe components were developed during the First World War as a mean to
quickly deliver fuel and water supplies to Allied forces. Following the war,
this
efficient method of joining pipes was adapted for everyday use in modern
society.
Given their ease of use and adaptable characteristics, grooved pipes have
developed into a very important industry in North America, as well as in other
= 20 regions.
Several different types of suppliers, distributors and manufacturers are
currently
involved in the production and distribution of grooved pipes and their
associated
products, which are used in industries of various types. As an example,
grooved
pipes are used for, but not limited to, the mining industry, the pulp and
paper
= 25 industry, the oil and gas industry, the power generation
industry, institutional facilities
and many other industries requiring fluid handling applications.
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In terms of applications, grooved pipes are usually used for, but not limited
to,
heating, ventilation and air conditioning (1-IVAC), fire Suppression Systems,
water
distribution, waste removal and oil field operations.
As will be detailed below, in certain circumstances, the lifespan of grooved
pipes can
be greatly enhanced by the combination of such pipes with a sacrificial anode
system.
A sacrificial anode or sacrificial rod is a metallic anode used in cathodic
protection,
where it is intended to be dissolved to protect other metal cornponents. The
main
idea is that the more active metal (i.e. the anode) oxidized more easily than
the
protected metal (i.e. the cathode) and corrodes first, hence the term
sacrificial.
Generally, the anode oxidizes nearly completely before the less active metal
will
corrode, therefore acting as a barrier against corrosion for the protected
metal.
As shown in Figure 1, when the sacrificial anode 16 is attached to a metal
structure
11 to be protected, and the two are submersed in water or buried in the earth
50, an
electrochemical cell is created. The earth or the water provides the ionic
pathway
necessary for cathodic protection to take place. Therefore, simply bolting a
piece of
active metal such as zinc to a less active metai, such as mild steel, and
leaving it in
the open air does not provide any protection, in the absence of the ionic
pathway
essential to cathodic protection.
=
Sacrificial anodes were discovered in the 1800s and have evolved a great deal
since
then. They are currently most commonly used, but are not limited to, the
protection
of underground water pipe lines, underground fuel pipe lines, underground
storage
tanks, steel pier piles, ship hulls (for both salted and fresh water),
offshore oil
platforms and outboard marine engines (for both salted and fresh water).
In the absence of the cathodic protection provided by the sacrificial anodes,
the
corrosion ratz., of the above mentioned structures would greatly increase.
Consequently, the overall cost associated with the corrosion of the structures
for
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individuals, businesses and government would be devastating. For example,
without
sacrificial anodes, water mains would never last the 30 plus years they are
currently
expected to.
Once an anode has expired, it usually can simply be replaced with a new one
(i.e.
once the anode is corroded away, it can be replaced with an uncorroded one).
Anodes come in all shapes and sizes and are typically alloys of zinc,
magnesium
and aluminum.
It is important to bear in mind that for a sacrificial anode to work, both the
structure
and the anode must simultaneously be buried into the earth or submersed in
water.
It is the earth or the water that provides the ionic pathway to complete the
electrochemical cell necessary for cathodic protection. Therefore, attaching
an
anode to a non submersed or buried pipe would provide no protection
whatsoever.
Consequently, there is still presently a need for a sacrificial anode system
that can
be used in a non-submersed or non-buried pipe.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a system that addresses at
least one
of the above-mentioned needs.
According to a first aspect of the present invention, there is provided a
sacrificial
anode system installable at an interface between a first pipe and a second
pipe. The
sacrificial anode system comprises an insertion sleeve shaped to fit along an
inner
surface of the first pipe; a flange attached to the insertion sleeve and
shaped to rest
against an end surface of the first pipe; a sacrificial anode to be positioned
within the
first pipe; and a stem linking the sacrificial anode to the insertion sleeve.
When used in combination with pipes provided with a ridge on the inner side of
the
pipe and proximate to the pipe end, the insertion sleeve and the flange of the
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sacrificial anode system preferably comprise a slotted opening extending
perpendicularly along the entire length of the insertion sleeve and the
flange.
Still when used in combination with pipes provided with a ridge on the inner
side of
the pipe and proximate to the pipe end, the insertion sleeve is preferably
further
provided with a groove running along the circumference of the insertion
sleeve,
proximate to the flange.
According to a second aspect of the present invention, there is also provided
a
method for maintaining a surface pipe system. The method comprises the steps
of:
a) providing a plurality of sacrificial anode systems for installation at
various
interfaces between adjacent pipes; b) installing the sacrificial anode systems
at the
interfaces; c) noting information related to the installation of the
sacrificial anode
systems; d) recording the information in a database; and e) scheduling
maintenance
activities based on the information recorded in the database.
Preferably, the sacrificial anode systems referred to, in the above-mentioned
method
for maintaining a surface pipe system, are sacrificial anode systems according
to the
first aspect of the present invention.
Still preferably, the database used in steps d) and e) of the method for
maintaining a
surface pipe system is a computerized database.
Alternatively, an additional step of physically tagging the pipes with at
least one of
the information recorded in the database can also be provided.
Other features of the present invention will become more apparent from the
following
description of preferred embodiments, and in reference to the appended
drawings,
given as examples only as to show how the invention may be put into practice.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 (PRIOR ART) is a schematic view of a prior art sacrificial anode
system.
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Figure 2 is a perspective view of a sacrificial anode system according to a
preferred
embodiment of the present invention.
=
Figure 3 is a side view of the sacrificial anode system shown in Figure 1.
Figure 4 is a cross-sectional view of a grooved pipe.
5 Figure 5 is a cross-sectional view of a sacrificial anode system
according to a
preferred embodiment of the present invention installed in the grooved pipe
shown in
Fioure 4.
Figure 6 is a side view of a grooved pipe showing the interface between two
grooved
pipe elements and a partial cut away view showing the sacrificial anode
according to
a preferred embodiment of the present invention.
= Figure 7 is a perspective view of a preferred embodiment of the insertion
sleeve and
the flange of the sacrificial anode system of the present invention.
Figure 8 is another perspective view of the insertion sleeve and the flange
according
to the preferred embodiment shown in Figure 7.
Figure 9 is a perspective detailed view of the insertion sleeve and the flange
according to the preferred embodiment shown in Figure 7.
Figure 10 is a perspective view of an alternative embodiment of the insertion
sleeve
and the flange of the sacrificial anode system of the present invention,
wherein the
insertion sleeve and the flange are provided with an opening and the insertion
sleeve
is provided with a sleeve groove.
Figure 11 is another perspective view of the insertion sleeve and the flange
according to the alternative embodiment shown in Figure 10.
Figure 12 is a perspective detailed view of the insertion sleeve and the
flange
= according to the alternative embodiment shown in Figure 10.
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Figure 13A is a perspective partial view of one type of grooved pipe that can
be used
in connection with the sacrificial anode system according to a preferred
embodiment
of the present invention, wherein the pipe is provided with an inner ridge
along its
inner surface and proximate to the pipe end.
Figure 13B is a perspective partial view of another type of grooved pipe that
can be
used with the sacrificial anode system according to a preferred embodiment of
the
present invention, wherein the inner surface of the pipe is free of inner
ridge.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE
INVENTION
The system according to the present invention, which will be described in
details
below, will be commercialized under the name Scipsa Tm system, the acronym
standing for "Self-Contained Ionic Pathway Sacrificial Anode" system. The
system is
a two-part anti-corrosion and maintenance product designed to protect surface
pipes
and associated parts by providing an unobtrusive, easy to install, sacrificial
anode
that can be placed inside of surface pipes. The addition of the sacrificial
anode
system according to the present invention to a surface pipe system will help
to
increase the lifespan of the surface pipe system and associated components.
Given that surface pipes and valve systems are in open air and that there is
therefore no ionic pathway to close the circuit between the anode and the
metal
pipe, up until now, surface pipe systems were typically non compatible with
sacrificial
anodes. By allowing the sacrificial anode to be placed inside the pipe, the
present
system allows sacrificial anode to utilize the pipes' own fluid as the ionic
pathway
necessary for cathodic protection, hence the term "Self Contained Ionic
Pathway".
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Advantageously, the system according to the present invention allows the
combination of sacrificial anodes with surface pipe systems, a combination
that was
not possible with conventional sacrificial anode.
By allowing the combination of sacrificial anodes with surface pipes, the
sacrificial
anode system according to the present invention helps prevent the corrosion of
surface pipes. The resulting decrease in the corrosion of surface pipes is
advantageous as, amongst other things, it increases health and safety,
increases
equipment protection, reduces the downtime of equipment due to repair and
maintenance, increases production time and reduces the overall costs of
equipment
in long term operations.
in the following description, similar features in the drawings have been given
similar
reference numerals and in order to way down the figures and facilitate their
understanding, some elements are not referred to in some figures if they were
already identified in a preceding one.
As shown in Figures 2, 3 and 5, according to a first aspect of the present
invention,
there is provided a sacrificial anode system 10 installable at an interface
between a
first pipe 100 and a second pipe 102. The sacrificial anode system comprises
an
insertion sleeve 12 shaped to fit along an inner surface of the first pipe
100; a flange
14 attached to the insertion sleeve 12 and shaped to rest against an end
surface of
the first pipe 100; a sacrificial anode 16 to be positioned within the first
pipe 100; and
a stern 18 linking the sacrificial anode to the insertion sleeve 12.
As can be seen in Figures 4 to 6, the addition of the sacrificial anode system
10 at
an interface of two pipes 100, 102 does not impact on the regular installation
of the
grooved pipes (i.e. the grooved pipes can be joined together using the same
components and techniques regardless of the presence of the sacrificial anode
system 10). The only difference between installing grooved pipes including the
sacrificial anode system 10 and grooved pipes without the sacrificial anode
system
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10, is the additional step of inserting the sacrificial anode system 10 inside
one of the
pipe 100 prior to joining the pipes 100, 102 using the clamp 20.
Figure 4 shows a cut away view of grooved pipes without the sacrificial anode
system 10, while Figures 5 and 6 show grooved pipes provided with the
sacrificial
anode system 10. As can be seen in the Figures, in both cases the pipe
structure
includes first and second pipes 100, 102 with a clamp 20 adapted to fit within
a pipe
groove 22, and affixed through a nut 34 and bolt 36 interface. In both cases,
the
interfaces are also provided with a rubber gasket or seal 24, for sealing the
joint and
preventing leakage.
In a preferred embodiment of this first aspect of the present invention, and
as better
illustrated in Figures 2 and 3, the insertion sleeve 12 is circular in order
to fit with the
normally circular form of the grooved pipes, but could have a different form
without
departing from the scope of the present invention, as will be apparent to one
skilled
in the art.
Preferably, the sacrificial anode system 10, according to this first aspect of
the
invention, will be manufactured with insertion sleeve 12 and flange 14 of
different
diameters, in order to accommodate the different diameters of the associated
grooved pipes.
Preferably the insertion sleeve 12 and the flange 14 are moulded from a single
piece
of material, but could also be attached together through other means such as
welding or the like.
Still preferably, the stem 18 linking the sacrificial anode 16 to the
insertion sleeve 12
is rigid, in order to stabilize the sacrificial anode 16 within the pipe 100,
and the
bottom side of the stem 18 and sacrificial anode 16 are curved in order to fit
the
normally circular form of the grooved pipes.
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As can be seen in Figures 13A and 13B, the sacrificial anode system can be
used
with different types of grooved pipes. These types of grooved pipes include
pipes
110 provided with a ridge on their inner surface and proximate to the pipe
end, as
better shown in Figure 13A, and pipes 112 without a ridge on their inner
surface
thereof, as illustrated in Figure 13B.
In a possible embodiment illustrated in Figures 7 to 9, the insertion sleeve
12A and
the flange 14A of the sacrificial anode system 10 form an integral structure
and the
surface of the insertion sleeve 12A is smooth. The sacrificial anode system 10
according to this embodiment is designed to be used with pipes 112 having a
smooth inner surface, as the one shown in figure 13B. Given the smooth inner
surface of the pipe 112, a sacriiicial anode system 10 according to this
embodiment,
and having a diameter matching that of the pipe in which it to be installed,
will easily
slide into the extremity of the corresponding pipe 112.
The installation of a sacrificial anode system 10 according to the above-
described
embodiment into the extremity of a pipe 110 having a ridge 104 on its inner
surface,
would however be problematic, since the ridge 104 would impede the insertion
of the
insertion sleeve 12A into the pipe 110.
Therefore, in an alternative embodiment, as better illustrated in Figures 10
to 12, the
insertion sleeve 12B and the flange 14B of the sacrificial anode system 10
comprise
a slotted opening 106 for adjustment of the diarneter of the insertion sleeve
123 and
the flange 14B upon insertion of said sleeve 12B into a pipe 110 comprising an
inner
ridge 104 along its inner surface. The opening 106 extends perpendicularly
along the
= entire length of the insertion sleeve 12B and the flange 14B, in order to
allow easy
contraction of the system 10. As a result, the diameter of the insertion
sleeve 12B
and the flange 14B will diminish when the insertion sleeve 12B travels over
the ridge
104 located on the inner side of the pipe 110, and therefore allow smooth
insertion of
the sacrificial anode system 10 according to this alternative embodiment into
pipes
= 110 of this type.
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Still referring to Figures 10 to 12, in this alternative embodiment, the
insertion sleeve
12B preferably further comprises a groove 108 (referred to as a sleeve groove)
shaped to fit over the inner ridge 104 along the inner surface of the pipe
110, once
the sacrificial anode system 10 is completely inserted into a pipe of this
type 110.
5 The sleeve groove 108 runs along the circumference of the insertion
sleeve 12B and
is located proximate to the flange 14B, since the inner ridge 104 of the pipe
110 is
usually located proximate to the pipe end. The sleeve groove 108 allows the
insertion sleeve 12B, to expand toward the inner side of the pipe 110 once the
position of the sleeve groove 108 matches that of the inner ridge 104, and
therefore,
10 provides a better fit of the sacrificial anode system 10 into pipes 110
of this type.
A second aspect of the invention relates to a method for maintaining a surface
pipe
system provided with a sacrificial anode system. The method is based on the
recording of the installation of the sacrificial anode system in a database
for the
purpose of future maintenance of the pipe system.
Knowing that sacrificial anodes have an expected life cycle, the steps of the
method
according to this second aspect of the invention are meant to ensure that the
pipe
systems maintain their integrity after the life cycle of the installed
sacrificial anode is
over.
Consequently, according to a second aspect of the present invention, there is
provided a method for maintaining a surface pipe system. The method comprises
the
steps of:
a) providing a plurality of sacrificial anode systems for installation at
various
interfaces between adjacent pipes;
b) installing said sacrificial anode systems at the interfaces;
c) noting information related to the installation of the sacrificial anode
systems;
d) recording the information in a database; and
e) scheduling maintenance activities based on the information recorded in the
database.
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in a preferred embodiment, the sacrificial anode system that is referred to in
step a)
and installed according to step b) is a sacrificial anode system 10
hereinabove
described in the first aspect of the present invention. The characteristics of
this
sacrificial anode system 10 were described above and need not be repeated
here.
Still in accordance with this preferred embodiment, the noted and recorded
information includes but is not limited to, the name of installer(s), the date
of the
installation, the location at the plant, mill, mine or the like and the life
expectancy of
the sacrificial anode. From this information, the expected replacement date of
the
sacrificial anode systems 10 can be estimated. This expected replacement date
can
also be included in the database.
Preferably, the above-mentioned database will be a computerized database. Such
a
computerized database allows the creation of associated software that can
provide
easy recording and consultation of the information by the concerned
individuals, as
well as easy scheduling of maintenance inspections and easy update of the
recorded information based on the result of those maintenance inspections.
At the time of installation, the string of pipes can also be tagged or marked
with a
pipe wrap that contains the above-mentioned information or a portion of it.
This
physical tagging of the pipes enables easy consultation of the relevant
information
= for maintenance technician, without having to resort to the above-
mentioned
database.
For exampie, if a pipe system comprising 1000 feet of pipes was installed at
ABC
plant and the system according to the present invention was incorporated to
the pipe
system by the installation of a sacrificial anode system 10 at every pipe
connection
(the sacrificial anode 18 used having a life expectancy of ten years). Using
the
method described hereinabove, a midway inspection can be scheduled to be
carried
by the maintenance personnel of the plant after half of the expected lifespan
of the
sacrificial anode has elapsed (i.e. after five years). This midway inspection
would
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,
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involve pulling apart a few random grooved pipes connections in order to
inspect the
condition of the sacrificial anodes 16 of the corresponding sacrificial anode
system
10. Given the result of the inspection, a replacement date for the sacrificial
anode
systems 10, based on the deteriorated condition of the sacrificial anodes 16,
can
then be determined. The information entered in the database can subsequently
be
updated to reflect these results.
The application of the above-mentioned method for maintaining a pipe system
provided with the sacrificial anode system 10 of the present invention results
in a
pipe system that is well maintained and corrosion free. Given that it is much
cheaper
to maintain a pipe system than it is to replace it, this solution can prove to
be cost
effective.
The scope of the claims should not be limited by the preferred embodiments set
forth
in the examples, but should be given the broadest interpretation consistent
with the
description as a whole.
